Prior and Rendering changes

[tbmiller-astro]

These are some backend changes to the priors and renderering modules mostly. Nothing user facing but changes to make upkeep a little easier and help with the planned addition of multi-band fitting. The main changes are as follows

• Rendering

  • Parameters now passed around in dictionaries rather than as arguments to the function
  • All render_{type} functions now return 3 arrays, the Fourier transform, the intrinsic image and the convolved image. If the method currently being used doesn't use one of these it results in zeros. The BaseRenderer class now has a method called combine_scene which takes these three inputs to produce the final model image. This should make it easier to add extra renderers and types of source.
  • For rendering multiple sources now takes a dictionary of all the source parameters rather than being seperated

• Priors

  • Commensurate with above the sampling now the sampling functions return the parameters in a dictionary
  • Sky sampling now move to separate classes
  • Better tools for dealing with suffixes for SourcePrior and MultiPrior

• misc.

  • added suffix arguments to all of the loss functions
  • added ability to reparam model for sampling
  • Changes to the test suites to work with all of the changes